Accessory

ABSTRACT

An interchangeable lens is removably attached to a camera body including a body-side mount, an image sensor, a plurality of body-side claws disposed outside of the image sensor and a plurality of elastic members respectively disposed on image sides of the body-side claws. The interchangeable lens includes the lens-side mount, first and third lens-side claws engaged with the plurality of body-side claws upon attachment to the camera body. The first and third lens-side claws project from the cylindrical portion in the outer periphery direction of the lens-side mount and extend in the circumferential direction around the optical axis. The first and third lens-side claws are in contact with the two elastic members opposite to each other across an optical axis in once upon attachment to the camera body.

INCORPORATION BY REFERENCE

The disclosure(s) of the following priority application(s) is hereinincorporated by reference: Japanese Patent Application No. 2017-206882filed Oct. 26, 2017.

TECHNICAL FIELD

The present invention relates to an accessory.

BACKGROUND ART

An accessory which can be removably attached to a camera body is known(for example, PTL1). Conventionally, it has been necessary to attach anaccessory to a camera body properly in a usable manner.

CITATION LIST Patent Literature

PTL1: Japanese Patent Laid-Open No. 8-43910

SUMMARY OF INVENTION

(1) In an accessory according to a first aspect of the presentinvention, the accessory can be removably attached to a camera body. Thecamera body includes: an image sensor which has a rectangular shapehaving an upper side, a lower side, a right side and a left side in acase where the camera body is horizontally held, the image sensorreceiving incident subject light centering around an optical axis;body-side terminal group including a plurality of body-side terminalsdisposed above the upper side of the image sensor; a ring-shapedbody-side mount disposed outside the image sensor and the body-sideterminal group, and the ring-shaped body-side mount being formedcentering around the optical axis; a first body-side projecting portionprojecting from the body-side mount in an inner diameter direction; afirst elastic member disposed on an image side of the first body-sideprojecting portion; a second body-side projecting portion projectingfrom the body-side mount in the inner diameter direction; a secondelastic member disposed on an image side of the second body-sideprojecting portion; a third body-side projecting portion projecting fromthe body-side mount in the inner diameter direction; a third elasticmember disposed on an image side of the third body-side projectingportion; a fourth body-side projecting portion projecting from thebody-side mount in the inner diameter direction; and a fourth elasticmember disposed on an image side of the fourth body-side projectingportion; wherein the first elastic member, the second elastic member,the third elastic member and the fourth elastic member are respectivelydisposed in four regions divided by a first body-side line which passesthrough a center in circumferential direction of the body-side terminalgroup and the optical axis, and a second body-side line which isorthogonal to the first body-side line at the optical axis. Theaccessory comprises: an accessory-side mount of a ring shape centeringaround the optical axis; the accessory-side mount being to be in contactwith the body-side mount; a cylindrical portion extending in the opticalaxis direction from an inner peripheral edge portion of theaccessory-side mount; accessory-side terminal group disposed inside thecylindrical portion; the accessory-side terminal group including aplurality of accessory-side terminals to be in contact with thebody-side terminals upon attachment to the camera body; a firstaccessory-side projecting portion projecting from the cylindricalportion in an outer periphery direction of the accessory-side mount andextending in a circumferential direction around the optical axis; and athird accessory-side projecting portion projecting from the cylindricalportion in the outer periphery direction of the accessory-side mount andextending in the circumferential direction around the optical axis;wherein: the first accessory-side projecting portion and the thirdaccessory-side projecting portion are in contact with two elasticmembers opposite to each other across the optical axis among the firstelastic member, the second elastic member, the third elastic member andthe fourth elastic member upon attachment to the camera body.

(2) In an accessory according to a second aspect of the presentinvention, the accessory can be removably attached to a camera bodyincluding: an image sensor receiving incident subject light centeringaround an optical axis; a ring-shaped body-side mount disposed outsidethe image sensor, the ring-shaped body-side mount being formed centeringaround the optical axis; a plurality of body-side projecting portionsprojecting from the body-side mount in an inner diameter direction; anda plurality of elastic members respectively disposed on image sides ofthe body-side projecting portions. The accessory comprises: anaccessory-side mount of a ring shape centering around the optical axis,the accessory-side mount being to be in contact with the body-sidemount; a cylindrical portion extending in the optical axis directionfrom an inner periphery edge portion of the accessory-side mount; afirst accessory-side projecting portion projecting from the cylindricalportion in an outer periphery direction of the accessory-side mount andextending in a circumferential direction around the optical axis; and athird accessory-side projecting portion projecting from the cylindricalportion in the outer periphery direction of the accessory-side mount andextending in the circumferential direction around the optical axis,wherein: the first accessory-side projecting portion and the thirdaccessory-side projecting portion are in contact with two elasticmembers opposite to each other across the optical axis among theplurality of elastic members upon attachment to the camera body.

(3) In an accessory according to a third aspect of the presentinvention, the accessory can be removably attached to a camera bodyincluding a body-side mount, body-side terminal group, a plurality ofbody-side projecting portions and a plurality of elastic membersrespectively disposed on image sides of the plurality of body-sideprojecting portions. The accessory comprises: an accessory-side mount ofa ring shape centering around the optical axis, the accessory-side mountbeing in contact with the body-side mount; a cylindrical portionextending in the optical axis direction from an inner peripheral edgeportion of the accessory-side mount; accessory-side terminal groupdisposed inside the cylindrical portion, the accessory-side terminalgroup including a plurality of accessory-side terminals to be in contactwith the body-side terminals upon attachment to the camera body; a firstaccessory-side projecting portion projecting from the cylindricalportion in an outer periphery direction of the accessory-side mount andextending in a circumferential direction centering around the opticalaxis; and a third accessory-side projecting portion projecting from thecylindrical portion in the outer periphery direction of theaccessory-side mount and extending in the circumferential directioncentering around the optical axis, wherein: the first accessory-sideprojecting portion and the third accessory-side projecting portion arein contact with two elastic members opposite to each other across theoptical axis among the plurality of elastic members upon attachment tothe camera body.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view schematically illustrating aconfiguration of a camera system.

FIG. 2 is a front view of a mount surface of a camera body, as seen froman interchangeable lens side.

FIG. 3 is a front view of the mount surface of the camera body, as seenfrom the interchangeable lens side.

FIG. 4 is a front view of a flat spring at a body-side mount.

FIG. 5 is a front view of a mount surface of the interchangeable lens,as seen from the camera body side.

FIG. 6 is a front view of the mount surface of the interchangeable lens,as seen from the camera body side.

FIG. 7 is a perspective view of the mount surface of the interchangeablelens.

FIG. 8 is a front view of a body-side claw portion and a lens-side clawportion at an insertion position, as seen from the interchangeable lensside.

FIG. 9 is a front view of the body-side claw portion and the lens-sideclaw portion at an attachment position, as seen from the interchangeablelens side.

FIG. 10 is a front view and a side view of the body-side claw portionand the lens-side claw portion in an over-rotated state in an attachingdirection, as seen from the interchangeable lens side.

FIG. 11 is a side view of the body-side claw portion and the lens-sideclaw portion in the over-rotated state in a removing direction, as seenfrom the interchangeable lens side.

FIG. 12 is a front view of the body-side claw portion and the lens-sideclaw portion in a first erroneous insertion state, as seen from theinterchangeable lens side.

FIGS. 13A,13B and 13C are front views of the body-side claw portion andthe lens-side claw portion in a second erroneous insertion state, athird erroneous insertion state and a fourth erroneous insertion state,as seen from the interchangeable lens side.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a cross-sectional view illustrating outline of a configurationof a camera system 1 according to an embodiment of the invention. Thecamera system 1 includes a camera body 2, and an interchangeable lens 3as one example of an accessory which can be removably attached to thecamera body 2. Other examples of the accessory which can be removablyattached to the camera body 2 can include a mount adapter, a teleconverter, a wide converter, or the like.

The interchangeable lens 3 includes a lens-side mount 310, a lens-sideterminal holding unit 320, a lens-side CPU 330, a lens-sidecommunication unit 340, a lens-side storage unit 350, an imaging opticalsystem 360 and a driving unit 370. The lens-side mount 310 and thelens-side terminal holding unit 320 will be described in detail later.

The lens-side CPU 330 is configured with a microcomputer, its peripheralcircuits, or the like. The lens-side communication unit 340 performspredetermined data communication with the camera body 2. The lens-sidecommunication unit 340 is connected to lens-side terminals (which willbe described later) provided at the lens-side terminal holding unit 320,and the lens-side CPU 330. The lens-side storage unit 350 is anon-volatile storage medium. The lens-side storage unit 350 is connectedto the lens-side CPU 330. In the lens-side storage unit 350, apredetermined control program, or the like, to be executed by thelens-side CPU 330 is stored in advance. The lens-side CPU 330 controlsthe interchangeable lens 3 by loading the control program from thelens-side storage unit 350 and executing the program.

The imaging optical system 360 causes a subject image to be formed on animaging surface of an image sensor 270 which will be described later. Anoptical axis O of the imaging optical system 360 coincides with centralpositions of the lens-side mount 310 and a body-side mount 210 whichwill be described later. The imaging optical system 360 in FIG. 1schematically includes a lens 361, a focusing lens 362 and a lens 363.The focusing lens 362 is a lens for adjusting a position where thesubject image is formed. The driving unit 370 is connected to thelens-side CPU 330, and includes an actuator, or the like, which is notillustrated. The driving unit 370 moves the focusing lens 362 back andforth in a direction of the optical axis O (+Z or −Z direction) by thisactuator, or the like.

The camera body 2 includes the body-side mount 210, a body-side terminalholding unit 220, a body-side CPU 230, a body-side communication unit240, a body-side storage unit 250, a power supplying unit 260 and theimage sensor 270. The body-side mount 210 and the body-side terminalholding unit 220 will be described in detail later.

The body-side CPU 230 is configured with a microcomputer, its peripheralcircuits, or the like. Note that the body-side CPU 230 performs variouskinds of control on the camera body. The body-side communication unit240 performs predetermined data communication with the interchangeablelens 3. The body-side communication unit 240 is connected to a pluralityof body-side terminals (which will be described later) provided at thebody-side terminal holding unit 220, and the body-side CPU 230.

The body-side storage unit 250 is a non-volatile storage medium. Thebody-side storage unit 250 is connected to the body-side CPU 230. In thebody-side storage unit 250, a predetermined control program, or thelike, to be executed by the body-side CPU 230 is stored in advance. Thebody-side CPU 230 controls the camera body 2 by loading the controlprogram from the body-side storage unit 250 and executing the program.

The power supplying unit 260 includes a power supply, and supplies powerto device inside of the camera body 2 and the interchangeable lens 3.The power supplying unit 260 is connected to the body-side terminals(which will be described later) provided at the body-side terminalholding unit 220 and the body-side CPU 230. The image sensor 270 is, forexample, a solid image sensor such as a CCD and a CMOS. The image sensor270 is connected to the body-side CPU 230, captures a subject andoutputs an imaging signal. Explanation regarding processing on theimaging signal outputted will be omitted.

Explanation of Lens Mount Mechanism

The camera system 1 of the present embodiment includes a so-calledbayonet lens mount mechanism. The body-side mount 210 provided at thecamera body 2 and the lens-side mount 310 provided at theinterchangeable lens 3 will be explained below in order.

Body-Side Mount 210

FIG. 2 and FIG. 3 are diagrams schematically illustrating a mount of thecamera body 2, as seen from the interchangeable lens 3 side. Referringnumber 44 is shown as a rotating direction of the interchangeable lens 3when the interchangeable lens 3 is attached to the camera body 2. Therotating direction or attaching direction 44 is a direction seen fromthe interchangeable lens 3. FIG. 2 and FIG. 3 illustrate the camera body2 being held in a laterally holding or in a horizontally holding. Asillustrated in FIG. 2, in the case where the camera body 2 ishorizontally held in the laterally holding, a rectangular image sensor270 is placed so that the longitudinal direction of the image sensor 270extends in a horizontal or lateral direction, that is, so that longsides become an upper side and a lower side, and short sides become aright side and a left side.

A first body-side line B1 extending in a vertical direction Y of thecamera body 2, indicated with a solid line in FIG. 2 is in a verticaldirection seen from a photographer who laterally holds the camera body 2in the laterally holding using the camera system 1. A second body-sideline B2 extending in a horizontal direction X of the camera body 2,indicated with a solid line in FIG. 2 is in a horizontal direction seenfrom the photographer who laterally holds the camera body 2 in thelaterally holding using the camera system 1.

Note that direction X is a horizontal direction or lateral direction anddirection Y is a vertical direction or longitudinal direction.

The first body-side line B1 is orthogonal to the second body-side lineB2 on the optical axis O (center). Lines B3 and B4 indicated with adashed-dotted line in FIG. 2 extend in directions intersecting with thefirst body-side line B1 and the second body-side line B2 on the opticalaxis O of the image sensor 270 at 45 degrees. These Lines B3 and B4 arereferred to as a third body-side line B3 and a fourth body-side line B4.

The mount of the camera body 2 comprises the body-side mount 210 and thebody-side terminal holding unit 220 mentioned above in FIG. 1. Thebody-side mount 210 includes a ring-shaped reference surface 211 whichhas a fixed width and which is disposed along a surface orthogonal tothe optical axis O. Further, the body-side mount 210 includes a firstbody-side claw portion 290 a, a second body-side claw portion 290 b, athird body-side claw portion 290 c and a fourth body-side claw portion290 d.

In the following description, these four first body-side claw portion290 a to fourth body-side claw portion 290 d which are projectingportions will be collectively referred to as a body-side claw portion290.

The body-side claw portions 290 are disposed along a circular opening212 of the body-side mount 210 at intervals. As illustrated in FIG. 2,the first body-side claw portion 290 a, the second body-side clawportion 290 b, the third body-side claw portion 290 c and the fourthbody-side claw portion 290 d are respectively disposed at an upper rightposition, at an upper left position, at a lower left position and at alower right position. The first body-side claw portion 290 a is disposedin a region above the second body-side line B2 and on a right side ofthe first body-side line B1, the second body-side claw portion 290 b isdisposed in a region above the second body-side line B2 and on a leftside of the first body-side line B1, the third body-side claw portion290 c is disposed in a region below the second body-side line B2 and ona left side of the first body-side line B1, and the fourth body-sideclaw portion 290 d is disposed in a region below the second body-sideline B2 and on a right side of the first body-side line B1.

The first body-side claw portion 290 a and the third body-side clawportion 290 c are respectively disposed in regions which are on thefourth body-side line B4 and which are substantially symmetric about theoptical axis O. The second body-side claw portion 290 b and the fourthbody-side claw portion 290 d are respectively disposed in regions whichare on the third body-side line B3 and which are substantially symmetricabout the optical axis O.

Note that, as illustrated in FIG. 2, each of central positions or areasof the first body-side claw portion 290 a to the fourth body-side clawportion 290 d in relation to respective circumferential directionsoverlaps with neither the third body-side line B3 nor the fourthbody-side line B4.

As illustrated in FIG. 3, lengths of the circumferential directions ofthe first body-side claw portion 290 a to the fourth body-side clawportion 290 d are different from each other. Specifically, the length ofthe first body-side claw portion 290 a is the longest, the length of thethird body-side claw portion 290 c is the second longest, the length ofthe fourth body-side claw portion 290 d is the third longest, and thelength of the second body-side claw portion 290 b is the shortest.

An angle α1 formed by a line connecting one end of the first body-sideclaw portion 290 a and the optical axis O and a line connecting theother end of the first body-side claw portion 290 a and the optical axisO is approximately 47 degrees, and is between 46.5 degrees and 47.5degrees.

An angle α3 formed by a line connecting one end of the third body-sideclaw portion 290 c and the optical axis O and a line connecting theother end of the third body-side claw portion 290 c and the optical axisO is approximately 42.5 degrees, and is between 42.0 degrees and 43.0degrees.

An angle α4 formed by a line connecting one end of the fourth body-sideclaw portion 290 d and the optical axis O and a line connecting theother end of the fourth body-side claw portion 290 d and the opticalaxis O is approximately 42 degrees, and is between 41.5 degrees and 42.5degrees.

An angle α2 formed by a line connecting one end of the second body-sideclaw portion 290 b and the optical axis O and a line connecting theother end of the second body-side claw portion 290 b and the opticalaxis O is approximately 40 degrees, and is between 40.0 degrees and 41.0degrees.

Lengths of the first body-side claw portion 290 a to the fourthbody-side claw portion 290 d in a radial direction (heights of the clawportions) are the same. Further, lengths of the first body-side clawportion 290 a to the fourth body-side claw portion 290 d in the opticalaxis O direction (thicknesses of the claw portions) are the same.

The body-side claw portion 290 projects toward the optical axis O(center of the image sensor 270) from the opening 212 of the body-sidemount 210. There are a portion where the body-side claw portion 290exists and a portion where the body-side claw portion 290 does not existon a circumference of the opening 212. In the following explanation,space 280 a between the first body-side claw portion 290 a and thefourth body-side claw portion 290 d on the circumference of the opening212 of the body-side mount 210 will be referred to as a first body-sidethrough portion 280 a.

Note that a through portion is also called as an attaching/removingportion where each end of the lens-side claw portions 290 a-290 d passthrough in attaching operation and removing operation.

In a similar manner, space 280 b between the first body-side clawportion 290 a and the second body-side claw portion 290 b will bereferred to as a second body-side through portion 280 b, space 280 cbetween the second body-side claw portion 290 b and the third body-sideclaw portion 290 c will be referred to as a third body-side throughportion 280 c, and space 280 d between the third body-side claw portion290 c and the fourth body-side claw portion 290 d will be referred to asa fourth body-side through portion 280 d. These first body-side throughportion 280 a to fourth body-side through portion 280 d which are fourspaces will be collectively referred to as a body-side through portion280.

Lengths of the first body-side through portion 280 a to the fourthbody-side through portion 280 d in the circumferential direction aredifferent from each other. Specifically, the third body-side throughportion 280 c is the longest, the first body-side through portion 280 ais the second longest, the fourth body-side through portion 280 d is thethird longest, and the second body-side through portion 280 b is theshortest.

An angle β3 formed by a line connecting one end of the third body-sidethrough portion 280 c and the optical axis O and a line connecting theother end of the third body-side through portion 280 c and the opticalaxis O is approximately 51 degrees, and is between 51.0 degrees and 52.0degrees.

An angle β1 formed by a line connecting one end of the first body-sidethrough portion 280 a and the optical axis O and a line connecting theother end of the first body-side through portion 280 a and the opticalaxis O is approximately 50 degrees, and is between 50.0 degrees and 51.0degrees.

An angle β4 formed by a line connecting one end of the fourth body-sidethrough portion 280 d and the optical axis O and a line connecting theother end of the fourth body-side through portion 280 d and the opticalaxis O is approximately 46 degrees, and is between 45.5 degrees and 46.5degrees.

An angle β2 formed by a line connecting one end of the second body-sidethrough portion 280 b and the optical axis O and a line connecting theother end of the second body-side through portion 280 b and the opticalaxis O is approximately 39 degrees, and is between 39.0 degrees and 40.0degrees.

Of course, a sum of the angles α1 to α4 of the four first body-side clawportion 290 a to the fourth body-side claw portion 290 d and the anglesβ1 to β4 of the four first body-side through portion 280 a to the fourthbody-side through portion 280 d is 360 degrees.

The first body-side through portion 280 a is formed in a region abovethe third body-side line B3 and below the fourth body-side line B4, thesecond body-side through portion 280 b is disposed in a region above thethird body-side line B3 and above the fourth body-side line B4, thethird body-side through portion 280 c is formed in a region below thethird body-side line B3 and above the fourth body-side line B4, and thefourth body-side through portion 280 d is formed in a region below thethird body-side line B3 and below the fourth body-side line B4.

The first body-side through portion 280 a and the third body-sidethrough portion 280 c are respectively formed in regions which are onthe second body-side line B2 and which are substantially symmetric aboutthe optical axis O. The second body-side through portion 280 b and thefourth body-side through portion 280 d are respectively formed inregions which are on the first body-side line B1 and which aresubstantially symmetric about the optical axis O.

Note that, as illustrated in FIG. 2, each of central positions or areasof the first body-side through portion 280 a to the fourth body-sidethrough portion 280 d in relation with respective circumferentialdirections overlaps with neither the first body-side line nor the secondbody-side line B2.

The body-side terminal holding unit 220 including a plurality ofbody-side terminals is provided inside the opening 212 of the body-sidemount 210. The body-side terminal holding unit 220 has an arc shapecorresponding to a shape of the ring-shaped body-side mount 210. Thebody-side terminal holding unit 220 is disposed on an inner peripheryside of the opening 212 of the body-side mount 210 and above the imagesensor 270. The body-side terminal holding unit 220 is preferablydisposed at the center above the image sensor 270 as illustrated in FIG.2 and FIG. 3. That is, the center of the body-side terminal holding unit220 in the circumferential direction is preferably located on the firstbody-side line B1.

The first body-side claw portion 290 a is disposed on an upper rightregion of the body-side terminal holding unit 220, and the secondbody-side through portion 280 b is disposed on an upper left region ofthe body-side terminal holding unit 220. Therefore, an angle formed by aline connecting one end of the body-side terminal holding unit 220 andthe optical axis O and a line connecting the other end of the body-sideterminal holding unit 220 and the optical axis O is smaller than a sumof the angle α1 of the first body-side claw portion 290 a and the angleβ2 of the second body-side through portion 280 b.

As described above, the body-side terminal holding unit 220 is providedwith a plurality of body-side terminals. The plurality of body-sideterminals (which will be referred to as a body-side terminal group) aredisposed above the upper side of the image sensor 270 in an arc shape.The body-side terminals are respectively conductive pins. The body-sideterminals are urged toward the −Z direction (FIG. 1) by a spring, or thelike, which is not illustrated.

The −Z direction is, that is, a direction from the camera body 2 towardthe interchangeable lens 3, and is a direction toward the subject. The+Z direction is, that is, a direction from the interchangeable lens 3toward the camera body 2, and is a direction toward the image sensor270.

The body-side mount 210 has a hole through which a lock pin 214 passes.In FIGS. 2 and 3, the hole through which the lock pin 214 passes isformed on an upper right region of the fourth body-side claw portion 290d. That is, on a ring-shaped reference surface 211 of the body-sidemount 210, the hole of the lock pin 214 is provided between a regionwhere the fourth body-side claw portion 290 d exists and a region wherethe first body-side claw portion 290 a exists. The lock pin 214 is urgedtoward the −Z direction (the subject side) by a spring, or the like,which is not illustrated. The lock pin 214 can move to the +Z direction(to the image sensor 270) against urging force of the spring by anunlocking button which is not illustrated being depressed.

FIG. 4 is a schematic diagram of the mount of the camera body 2 fromwhich the body-side mount 210 is removed, as seen from theinterchangeable lens 3 side. A first flat spring 213 a is provided at aposition corresponding to the first body-side claw portion 290 a or onthe back side of the first body-side claw portion 290 a.

In a similar manner, a second flat spring 213 b is provided at aposition corresponding to the second body-side claw portion 290 b or onthe back side of the second body-side claw portion 290 b, a third flatspring 213 c is provided at a position corresponding to the thirdbody-side claw portion 290 c or on the back side of the third body-sideclaw portion 290 c, and a fourth flat spring 213 d is provided at aposition corresponding to the fourth body-side claw portion 290 d on theback side of the fourth body-side claw portion 290 d.

In the following explanation, these four first flat spring 213 a to thefourth flat spring 213 d will be collectively referred to as a flatspring 213. The flat spring 213 is disposed on a surface confronting theimage sensor 270 of the body-side claw portion 290, and urges thecorresponding lens-side claw portion (which will be described later) 390to the image sensor 270 (+Z direction).

As illustrated in FIG. 4, a rear end or trailing end portion of thebody-side terminal holding unit 220 in the attaching direction 44 (shownin FIG. 2) is disposed near a line B5 which connects the optical axis Oand a rear end or trailing end portion of the first flat spring 213 a inthe attaching direction 44 (which will be described later). The secondflat spring 213 b, the third flat spring 213 c and the fourth flatspring 213 d are disposed around the optical axis O at intervals ofapproximately 90 degrees from the first flat spring 213 a.

Lens-Side Mount 310

FIG. 5 and FIG. 6 are diagrams schematically illustrating the mount ofthe interchangeable lens 3 seen from the camera body 2 side (seen fromback of the interchangeable lens 3). A first lens-side line L1 extendingin a vertical direction Y of the interchangeable lens 3, indicated witha solid line in FIG. 5 is in a vertical direction seen from aphotographer who laterally holds the camera body 2 in the laterallyholding using the camera system 1. Further, a second lens-side line L2extending in a horizontal direction X of the interchangeable lens 3,indicated with a solid line in FIG. 5 is in a horizontal direction seenfrom the photographer who laterally holds the camera body 2 in thelaterally holding using the camera system 1.

The first lens-side line L1 is orthogonal to the second lens-side lineL2 on the optical axis O (center) of the interchangeable lens 3. Asindicated with a dashed-dotted line in FIG. 5, lines extending indirections intersecting with the first lens-side line L1 and the secondlens-side line L2 on the optical axis O at 45 degrees are referred to asa third lens-side line L3 and a fourth lens-side line L4. With theinterchangeable lens 3 attached to the camera body 2 in a usable manner,the first body-side line B1 is aligned with the first lens-side line L1,the second body-side line B2 is aligned with the second lens-side lineL2, the third body-side line B3 is aligned with the fourth lens-sideline L4, and the fourth body-side line B4 is aligned with the thirdlens-side line L3. Note that the lines do not have to completely arealigned with each other, and a gap may occur within a range in which theinterchangeable lens 3 can be properly attached to the camera body 2 ina usable manner.

The mount of the interchangeable lens 3 includes the lens-side mount 310and the lens-side terminal holding unit 320 mentioned above in FIG. 1.The lens-side mount 310 is formed in a circular shape centering aroundthe optical axis O of the interchangeable lens 3, and is disposed alonga surface orthogonal to the optical axis O. The lens-side mount 310 hasa reference surface 311 which is to be in contact with the referencesurface 211 of the body-side mount 210 once the interchangeable lens 3is attached to the camera body 2. The reference surface 311 has acircular shape centering around the optical axis O, and is disposedalong a surface orthogonal to the optical axis O. On a rear end surfaceof the reference surface 311 in the optical axis O direction, a slidesurface for the lock pin 309 is formed in a concave shape recessedtoward the −Z direction on a cross-section along the Z direction. Aslide surface for the lock pin 309 allows the lock pin 214 which will bedescribed later to slide in contacting state during the interchangeablelens 3 being attached. The slide surface for the lock pin 309 has acircular shape centering around the optical axis O, and is disposedalong a surface orthogonal to the optical axis O.

The lens-side mount 310 is fixed by being screwed at a fixing memberdisposed inside the interchangeable lens 3 using screws 313. In the casewhere the lens-side mount 310 is seen from the camera body 2 side, thescrews 313 are disposed around the optical axis O at intervals ofapproximately 90 degrees. Further, four screws 313 are respectivelydisposed on outer peripheries of four lens-side claw portions 390 whichwill be described later. Still further, the screws 313 are disposed onouter peripheries at both end portions of the lens-side terminal holdingunit 320 in the circumferential direction.

The lens-side mount 310 includes a cylindrical portion 312. Thecylindrical portion 312 extends in the direction along the optical axisO (herein after referred to as the optical axis O direction) at an innerperipheral edge portion of the lens-side mount 310, that is an innerperipheral edge portion of the reference surface 311. Once theinterchangeable lens 3 is attached to the camera body 2, a rear end ofthe cylindrical portion 312 in the optical axis O direction is locatedat the camera body 2 side than the reference surface 311. The lens-sidemount 310 includes a first lens-side claw portion 390 a, a secondlens-side claw portion 390 b, a third lens-side claw portion 390 c and afourth lens-side claw portion 390 d. These four lens-side claw portionsare arranged along an outer periphery of the rear end portion of thecylindrical portion 312 in the optical axis O direction at intervals.

In the following explanation, these four first lens-side claw portion390 a to fourth lens-side claw portion 390 d which are projectingportions will be collectively referred to as a lens-side claw portion390.

The lens-side claw portion 390 is provided at an outer peripheral edgeportion of the cylindrical portion 312 of the lens-side mount 310 toproject toward an outer periphery direction of the lens-side mount 310.The lens-side claw portion 390 is substantially orthogonal to theoptical axis O. Further, the lens-side claw portion 390 extends in thecircumferential direction around the optical axis O. As illustrated inFIG. 5 and FIG. 6, the first lens-side claw portion 390 a is disposed atan upper left position, the second lens-side claw portion 390 b isdisposed at an upper right position, the third lens-side claw portion390 c is disposed at a lower right position, and the fourth lens-sideclaw portion 390 d is disposed at a lower left position. That is, thefirst lens-side claw portion 390 a is disposed in a region which isabove the second lens-side line L2 and which is on the left side of thefirst lens-side line L1, the second lens-side claw portion 390 b isdisposed in a region which is above the second lens-side line L2 andwhich is on the right side of the first lens-side line L1, the thirdlens-side claw portion 390 c is disposed in a region which is below thesecond lens-side line L2 and which is on the right side of the firstlens-side line L1, and the fourth lens-side claw portion 390 d isdisposed in a region which is below the second lens-side line L2 andwhich is on the left side of the first lens-side line L1.

Further, the first lens-side claw portion 390 a and the third lens-sideclaw portion 390 c are respectively disposed in regions which are on thethird lens-side line L3 and which are substantially symmetric about theoptical axis O, and the second lens-side claw portion 390 b and thefourth lens-side claw portion 390 d are respectively disposed in regionswhich are on the fourth lens-side line L4 and which are substantiallysymmetric about the optical axis O.

Note that the third lens-side line L3 and the fourth lens-side line L4do not necessarily pass through the central positions of the firstlens-side claw portion 390 a to the fourth lens-side claw portion 390 din relation to respective circumferential directions.

Once the interchangeable lens 3 is attached to the camera body 2, thebody-side claw portion 290 is disposed between the lens-side mount 310and the lens-side claw portion 390 in the optical axis O direction. Atthis time, the first lens-side claw portion 390 a comes into contactwith the flat spring 213 a of the first body-side claw portion 290 a,the second lens-side claw portion 390 b comes into contact with the flatspring 213 b of the second body-side claw portion 290 b, the thirdlens-side claw portion 390 c comes into contact with the flat spring 213c of the third body-side claw portion 290 c, and the fourth lens-sideclaw portion 390 d comes into contact with the flat spring 213 d of thefourth body-side claw portion 290 d.

The lens-side claw portion 390 includes a urged portion as a contactportion which is urged in a direction away from the body-side clawportion 290 by being brought into contact with the flat spring 213. Notethat the urged portion may have any shape if the lens-side claw portion390 can receive sufficient urging force from the flat spring 213, andcontact between the flat spring 213 and the urged portion may be one ofpoint contact, line contact and surface contact. The flat spring 213 mayhave any shape and material if the flat spring 213 can sufficientlypress the lens-side claw portion 390, and the shape and the material canbe changed as appropriate.

Once the flat spring 213 of the body-side claw portion 290 comes intocontact with the lens-side claw portion 390, the lens-side claw portion390 is pressed in a direction (+Z direction) away from the body-sideclaw portion 290 along the optical axis O by the flat spring 213. By thelens-side claw portion 390 being pressed in the +Z direction (toward theimage sensor 270), the lens-side mount 310 is pressed toward thebody-side mount 210, and attachment between the camera body 2 and theinterchangeable lens 3 becomes stable.

Note that the lengths of the lens-side claw portion 390 and thebody-side claw portion 290 in the circumferential direction do not haveto be made the same, and the length of the lens-side claw portion 390 inthe circumferential direction can be changed as long as the flat spring213 can urge the lens-side claw portion 390. Further, the whole surfaceof the lens-side claw portion 390 does not have to face the wholesurface of the body-side claw portion 290 in a state where theinterchangeable lens 3 is attached to the camera body 2, and a positionof an end portion of the lens-side claw portion 390 in thecircumferential direction may be different from a position of an endportion of the body-side claw portion 290 in the circumferentialdirection.

Further, lengths of the lens-side claw portion 390 and the body-sidethrough portion 280 in the circumferential direction do not have to bemade substantially the same, and the length of the lens-side clawportion 390 to be inserted, in the circumferential direction only has tobe equal to or less than the length of the body-side through portion 280in the circumferential direction.

In a similar manner, lengths of the body-side claw portion 290 and thelens-side through portion 380 in the circumferential direction do nothave to be made the same, and the length of the body-side claw portion290 to be inserted, in the circumferential direction only has to beequal to or less than the length of the lens-side through portion 380 inthe circumferential direction.

As illustrated in FIG. 6, lengths of the first lens-side claw portion390 a to the fourth lens-side claw portion 390 d in the circumferentialdirection are different from one another. Further, angles respectivelyformed by lines connecting one ends of the first lens-side claw portion390 a to the fourth lens-side claw portion 390 d in the circumferentialdirection and the optical axis O and lines connecting the other ends ofthe first lens-side claw portion 390 a to the fourth lens-side clawportion 390 d in the circumferential direction and the optical axis Oare different from one another. Specifically, the third lens-side clawportion 390 c is the longest, the first lens-side claw portion 390 a isthe second longest, the fourth lens-side claw portion 390 d is the thirdlongest, and the second lens-side claw portion 390 b is the shortest.

An angle α7 formed by a line connecting one end of the third lens-sideclaw portion 390 c and the optical axis O and a line connecting theother end of the third lens-side claw portion 390 c and the optical axisO is approximately 48.5 degrees, and is between 48.0 degrees and 49.0degrees.

An angle α5 formed by a line connecting one end of the first lens-sideclaw portion 390 a and the optical axis O and a line connecting theother end of the first lens-side claw portion 390 a and the optical axisO is approximately 48 degrees, and is between 47.5 degrees and 48.5degrees.

An angle α8 formed by a line connecting one end of the fourth lens-sideclaw portion 390 d and the optical axis O and a line connecting theother end of the fourth lens-side claw portion 390 d and the opticalaxis O is approximately 44 degrees, and is between 43.0 degrees and 45.0degrees.

An angle α6 formed by a line connecting one end of the second lens-sideclaw portion 390 b and the optical axis O and a line connecting theother end of the second lens-side claw portion 390 b and the opticalaxis O is approximately 36 degrees, and is between 35.5 degrees and 36.5degrees.

Note that the angle α6 formed by the line connecting the one end of thesecond lens-side claw portion 390 b and the optical axis O and the lineconnecting the other end of the second lens-side claw portion 390 b andthe optical axis O is less than an angle of rotation required to rotatethe interchangeable lens 3 for attaching to the camera body 2.

The rotation angle will be described later.

Lengths of the first lens-side claw portion 390 a to the fourthlens-side claw portion 390 d in a radial direction (heights of the clawportions) are substantially the same. Further, lengths of the firstlens-side claw portion 390 a to the fourth lens-side claw portion 390 din the optical axis O (thicknesses of the claw portions) direction aresubstantially the same.

Note that at least one of the lens-side claw portions 390 may bepartially cut out as long as an attachment incompletion state betweenthe camera body 2 and the interchangeable lens 3 is not affected. In thecase where part of the first lens-side claw portion 390 a is cut out,the whole including a projecting portion and a cut out portion disposedin a region facing the first body-side claw portion 290 a is consideredto be the first lens-side claw portion 390 a. This will similarly applyto other second to fourth lens-side claw portions 390 b to 390 d. As away of cutting out the lens-side claw portion, the first lens-side clawportion 390 a may be cut out so as to be divided into two or moreportions in the circumferential direction, or may be cut out so thatpart of the first lens-side claw portion 390 a is cut out, or may be cutout so that a length of at least part of the first lens-side clawportion 390 a in the radial direction becomes shorter. Therefore, partof the lens-side claw portion 390 on the third lens-side line L3 or thefourth lens-side line L4 may be cut out.

Further, a length of the first lens-side claw portion 390 a in thecircumferential direction may be changed as long as the first lens-sideclaw portion 390 a passes through the corresponding first body-sidethrough portion 280 a upon insertion. This will similarly apply to thesecond lens-side claw portion 390 b, the third lens-side claw portion390 c and the fourth lens-side claw portion 390 d.

Still further, a thickness of the cylindrical portion 312 in the radialdirection can be changed as appropriate, and it is also possible toemploy a shape in which at least part projects to an inner diameter sideof the cylindrical portion 312 of the present embodiment.

The lens-side claw portion 390 projects outward in the radial directionfrom an outer periphery of the cylindrical portion 312, and there is aportion where the lens-side claw portion 390 exists and a space portionwhere the lens-side claw portion 390 does not exist on the outerperiphery of the cylindrical portion 312.

In the following explanation, space 380 d between the first lens-sideclaw portion 390 a and the fourth lens-side claw portion 390 d on theouter periphery of the cylindrical portion 312 will be referred to as afirst lens-side through portion 380 a.

In a similar manner, space 380 b between the first lens-side clawportion 390 a and the second lens-side claw portion 390 b will bereferred to as a second lens-side through portion 380 b, space 380 cbetween the second lens-side claw portion 390 b and the third lens-sideclaw portion 390 c will be referred to as a third lens-side throughportion 380 c, and space 380 d between the third lens-side claw portion390 c and the fourth lens-side claw portion 390 d will be referred to asa fourth lens-side through portion 380 d.

These four first lens-side through portion 380 a to fourth lens-sidethrough portion 380 d will be collectively referred to as a lens-sidethrough portion 380.

Lengths of the first lens-side through portion 380 a to the fourthlens-side through portion 380 d in the circumferential direction aredifferent from one another. Specifically, the second lens-side throughportion 380 b is the longest, the first lens-side through portion 380 ais the second longest, the fourth lens-side through portion 380 d is thethird longest, and the third lens-side through portion 380 c is theshortest.

An angle β6 formed by a line connecting one end of the second lens-sidethrough portion 380 b and the optical axis O and a line connecting theother end of the second lens-side through portion 380 b and the opticalaxis O is approximately 50 degrees, and is between 49.5 degrees and 50.5degrees.

An angle β5 formed by a line connecting one end of the first lens-sidethrough portion 380 a and the optical axis O and a line connecting theother end of the first lens-side through portion 380 a and the opticalaxis O is approximately 45 degrees, and is between 44.5 degrees and 45.5degrees.

An angle β8 formed by a line connecting one end of the fourth lens-sidethrough portion 380 d and the optical axis O and a line connecting theother end of the fourth lens-side through portion 380 d and the opticalaxis O is approximately 44.5 degrees, and is between 44.0 degrees and45.0 degrees.

An angle β7 formed by a line connecting one end of the third lens-sidethrough portion 380 c and the optical axis O and a line connecting theother end of the third lens-side through portion 380 c and the opticalaxis O is approximately 44 degrees, and is between 43.5 degrees and 44.5degrees.

Of course, a sum of the angles α5 to α8 of the four first lens-side clawportion 390 a to the fourth lens-side claw portion 390 d and the angles135 to 138 of the four first lens-side through portion 380 a to thefourth lens-side through portion 380 d is 360 degrees.

Further, the first lens-side through portion 380 a and the thirdlens-side through portion 380 c are respectively disposed in regionswhich are on the second lens-side line L2 and which are substantiallysymmetric about the optical axis O, and the second lens-side throughportion 380 b and the fourth lens-side through portion 380 d arerespectively disposed in regions which are on the first lens-side lineL1 and which are substantially symmetric about the optical axis O.

Note that the first lens-side line L1 and the second lens-side line L2do not have to pass through central positions in relation to thecircumferential direction of the first lens-side through portion 380 ato the fourth lens-side through portion 380 d.

The lens-side terminal holding unit 320 including a plurality oflens-side terminals is provided inside the cylindrical portion 312. Thelens-side terminal holding unit 320 has an arc shape corresponding to ashape of the ring-shaped lens-side mount 310. The lens-side terminalholding unit 320 is preferably disposed at an upper part of thelens-side mount 310 along the opening of the lens-side mount 310 anddisposed at the center of the upper part as illustrated in FIG. 5 andFIG. 6. That is, the center of the lens-side terminal holding unit 320in the circumferential direction is preferably located on the firstlens-side line L1.

The first lens-side claw portion 390 a is disposed on an upper left sideof the lens-side terminal holding unit 320, and the second lens-sidethrough portion 380 b is disposed on an upper right side of thelens-side terminal holding unit 320. Therefore, an angle formed by aline connecting one end of the lens-side terminal holding unit 320 andthe optical axis O and a line connecting the other end of the lens-sideterminal holding unit 320 and the optical axis O is smaller than a sumof the angle α5 of the first lens-side claw portion 390 a and the angleβ6 of the second lens-side through portion 380 b.

The lens-side terminal holding unit 320 has the plurality of lens-sideterminals as described above. The plurality of lens-side terminals(which will be referred to as a lens-side terminal group) are disposedat the lens-side terminal holding unit 320 in a line inside thelens-side mount 310 in an arc shape. The lens-side terminal group aredisposed so that respective conductive contact surfaces are exposedtoward +Z direction (FIG. 1).

All the contact surfaces of the plurality of lens-side terminals may belocated at a position in the +Z direction side from a rear end of thelens-side claw portion 390 in the optical axis O direction or may belocated at a position in the −Z direction side from the rear end of thelens-side claw portion 390 in the optical axis O direction.

Further, part of the contact surfaces of the plurality of lens-sideterminals may be located at a position in the +Z direction side from therear end of the lens-side claw portion 390 in the optical axis Odirection, and the remaining contact surfaces may be located at aposition in the −Z direction side from the rear end of the lens-sideclaw portion 390 in the optical axis O direction.

The lens-side mount 310 has a lock pin receiving portion 314. The lockpin receiving portion 314 is disposed on an upper left side of thefourth lens-side claw portion 390 d as illustrated in FIG. 5 and FIG. 6.That is, the lock pin receiving portion 314 is disposed between aportion corresponding to an outer periphery side of the first lens-sideclaw portion 390 a and a portion corresponding to an outer peripheryside of the fourth lens-side claw portion 390 d among the slide surfacefor the lock pin 309 of the lens-side mount 310.

The lock pin receiving portion 314 is a groove in which the lock pin 214of the camera body 2 fits once the interchangeable lens 3 is attached tothe camera body 2. This groove is provided in a concave shape recessedtoward the −Z direction (FIG. 1) from the slide surface for the lock pin309 of the lens-side mount 310.

In a state where the unlocking button of the camera body 2 is notdepressed, an end portion of the lock pin 214 in the −Z direction (frontend of the lock pin 214 on the subject side) fits in the lock pinreceiving portion 314 of the lens-side mount 310. Further, in a statewhere the unlocking button of the camera body 2 is depressed, an endportion of the lock pin 214 in the −Z direction is located at a positionin the +Z direction side from the slide surface for the lock pin 309.Therefore, rotating the interchangeable lens 3 and the camera body 2relatively to each other while the unlocking button of the camera body 2is depressed does not bring the lock pin 214 into contact with the slidesurface for the lock pin 309.

Once the interchangeable lens 3 is attached to the camera body 2, theplurality of body-side terminals respectively physically come intocontact with the corresponding plurality of lens-side terminals. By thiscontact, the plurality of body-side terminals are electrically connectedto the plurality of lens-side terminals. That is, the plurality ofbody-side terminals are electrically conductive with the plurality oflens-side terminals.

As illustrated in FIG. 7, a restriction pin 315 is disposed between thereference surface 311 of the lens-side mount 310 and the fourthlens-side claw portion 390 d and projects from an outer peripheralsurface of the cylindrical portion 312. The restriction pin 315 isdisposed on a rear end side or trailing side (position close to thethird lens-side claw portion 390 c) of the fourth lens-side claw portion390 d in the attaching direction 44. Part of the restriction pin 315 isdisposed on a back side of the fourth lens-side claw portion 390 d asthe fourth lens-side claw portion 390 d is seen from the back of theinterchangeable lens 3.

Note that, while, in the present embodiment, a screw member is used asthe restriction pin 315, and the restriction pin 315 is screwed at thecylindrical portion 312 from outside in the radial direction, the shapeand the material of the restriction pin 315 are not limited to this.

Method for Attaching Interchangeable Lens 3 to Camera Body 2

A method for attaching the interchangeable lens 3 to the camera body 2will be described next with reference to FIG. 8 and FIG. 9. FIG. 8 andFIG. 9 are diagrams illustrating positional relationship between thebody-side claw portion 290 of the camera body 2 and the lens-side clawportion 390 of the interchangeable lens 3, and are diagrams for making astate where the claw portions abut on each other understandable.Further, FIG. 8 and FIG. 9 are diagrams of the body-side mount 210 andthe lens-side mount 310, as seen from the subject side to the imagesensor 270 side (seen in the +Z direction), and the lens-side mount 310is horizontally inverted between FIG. 5 and FIG. 6.

When the interchangeable lens 3 is attached to the camera body 2, first,a position of an index (not illustrated) provided on the outerperipheral surface of the interchangeable lens 3 and a position of anindex (not illustrated) provided on an exterior surface of the camerabody 2 are aligned, the body-side mount 210 and the lens-side mount 310are made to face each other, and each lens-side claw portion 390 isinserted into each body-side through portion 280. That is, asillustrated in FIG. 8, the first lens-side claw portion 390 a isinserted into the first body-side through portion 280 a, the secondlens-side claw portion 390 b is inserted into the second body-sidethrough portion 280 b, the third lens-side claw portion 390 c isinserted into the third body-side through portion 280 c, and the fourthlens-side claw portion 390 d is inserted into the fourth body-sidethrough portion 280 d. At this time, the first body-side claw portion290 a is inserted into the second lens-side through portion 380 b, thesecond body-side claw portion 290 b is inserted into the third lens-sidethrough portion 380 c, the third body-side claw portion 290 c isinserted into the fourth lens-side through portion 380 d, and the fourthbody-side claw portion 290 d is inserted into the first lens-sidethrough portion 380 a. A position of the interchangeable lens 3 withrespect to the camera body 2 at this time will be referred to as aninsertion position and state where the interchangeable lens 3 at theinsertion position can be inserted to the camera body 2 is insertionstate.

The interchangeable lens 3 is rotated in the attaching direction 44illustrated in FIG. 8 from the above-described insertion position. Theattaching direction 44 is a direction along the circumferentialdirection around the optical axis O in a plane which is substantiallyorthogonal to the optical axis O. In association with rotation of theinterchangeable lens 3, the first body-side claw portion 290 a and theflat spring 213 a go into space between the first lens-side claw portion390 a and the reference surface 311.

Specifically, the interchangeable lens 3 is inserted in +Z direction,the first lens-side claw portion 390 a goes into the image sensor 270side (+Z side) of the first body-side claw portion 290 a, and the firstlens-side claw portion 390 a faces the image sensor 270 side (+Z side)of the flat spring 213 a. In conjunction with this, the first body-sideclaw portion 290 a and the flat spring 213 a go into space between thefirst lens-side claw portion 390 a and the reference surface 311. In asimilar manner, the second body-side claw portion 290 b and the flatspring 213 b go into space between the second lens-side claw portion 390b and the reference surface 311, the third body-side claw portion 290 cand the flat spring 213 c go into space between the third lens-side clawportion 390 c and the reference surface 311, and the fourth body-sideclaw portion 290 d and the flat spring 213 d go into space between thefourth lens-side claw portion 390 d and the reference surface 311. Atthis time, the lens-side terminals sequentially come into contact withthe body-side terminals.

Note that, while the interchangeable lens 3 is made to rotate in theattaching direction 44 with respect to the camera body 2, it is alsopossible to make the camera body 2 rotate in an opposite direction tothe attaching direction 44 with respect to the interchangeable lens 3.

FIG. 9 is a diagram of the interchangeable lens 3 which is rotated inthe attaching direction 44 by a first angle (herein after referred to asfirst rotating angle) with respect to the camera body 2 from theinsertion position in FIG. 8, and illustrates a state where attachmentof the interchangeable lens 3 to the camera body 2 is completed. Theposition of the interchangeable lens 3 at this time will be referred toas an attachment position. The first rotating angle is approximately 40degrees in the present embodiment, and is between 38.5 degrees and 41.5degrees.

At the attachment position, the lock pin 214 of the camera body 2 beingpushed to the −Z direction goes into the lock pin receiving portion 314of the interchangeable lens 3. After the lock pin 214 goes into the lockpin receiving portion 314, rotation of the interchangeable lens 3 to beremoved from the camera body 2 is restricted. That is, when eachbody-side claw portion 290 and each lens-side claw portion 390 face eachother completely in the attachment position of the interchangeable lens3, relative positions between the body-side mount 210 and the lens-sidemount 310 in the circumferential direction are determined.

Further, the lens-side claw portion 390 is pushed to the image sensor270 side (+Z direction) by the flat spring 213 and the reference surface311 of the lens-side mount 310 comes into contact with the referencesurface 211 of the body-side mount 210. By the lens-side mount 310 beingin surface contact with the body-side mount 210 and being urged by theflat spring 213, the interchangeable lens 3 is tightly attached to thecamera body 2.

At the attachment position, the plurality of lens-side terminalsrespectively come into contact with the corresponding plurality ofbody-side terminals, and are electrically connected to the plurality ofbody-side terminals.

Further, a state where each lens-side claw portion 390 is inserted intoeach corresponding body-side through portion 280 at the insertionposition in FIG. 8 until immediately before the attachment position inFIG. 9 will be referred to as an attachment incompletion state. Becausethe lock pin 214 of the camera body 2 is pushed in the −Z direction, inthe attachment incompletion state, an end portion of the lock pin 214 inthe −Z direction is in contact with the slide surface for the lock pin309 of the lens-side mount 310.

In association with rotation of the interchangeable lens 3, the endportion of the lock pin 214 in the −Z direction slides on the slidesurface for the lock pin 309 of the interchangeable lens 3. Therefore,in a first rotating angle range in an opposite direction to theattaching direction 44 from the lock pin receiving portion 314 of theslide surface for the lock pin 309, a fixing screw for fixing thelens-side mount 310 is not disposed. By a fixing screw not beingdisposed in the above-described first rotating angle range in theopposite direction, because the end portion of the lock pin 214 in the−Z direction does not abut on the fixing screw as the end portion of thelock pin 214 slides on the slide surface for the lock pin 309, it ispossible to smoothly attach and remove the interchangeable lens 3.

Method for Removing Interchangeable Lens 3 from Camera Body 2

If a user depresses the unlocking button which is not illustrated of thecamera body at the attachment position, the lock pin 214 evacuates fromthe lock pin receiving portion 314 to the image sensor 270 side. By thismeans, restriction on rotation of the interchangeable lens 3 withrespect to the camera body 2 is cancelled, so that the lens-side mount310 is allowed to rotate with respect to the body-side mount 210. If theinterchangeable lens 3 is rotated in a direction opposite to theattaching direction 44 (removing direction) with respect to the camerabody 2 while the unlocking button which is not illustrated is depressed,each lens-side claw portion 390 moves to a position of each body-sidethrough portion 280 from a position facing an image side surface of eachbody-side claw portion 290, and reaches the insertion positionillustrated in FIG. 8.

Explanation of an Over-rotated State in Attaching Direction

An over-rotated state where the interchangeable lens 3 is rotated in theattaching direction 44 with respect to the camera body 2 by equal to orgreater than the first rotating angle will be described next withreference to FIG. 10. FIG. 10 is a schematic diagram illustratingpositional relationship between the fourth body-side claw portion 290 dof the camera body 2 and the fourth lens-side claw portion 390 d of theinterchangeable lens 3. A part (a) on an upper side of a dashed-dottedline is a diagram seen from the subject side to the image sensor 270side, and a part (b) on a lower side of the dashed-dotted line is adiagram of a lens mount mechanism seen from a side. In an operation ofattaching the interchangeable lens 3 to the camera body 2, if the userrotates the interchangeable lens 3 in the attaching direction 44 whiledepressing the unlocking button, the lock pin 214 does not go into thelock pin receiving portion 314 at the attachment position. Therefore, itis possible to rotate the interchangeable lens 3 further from theattachment position illustrated in FIG. 9 with respect to the camerabody 2. In the case where the interchangeable lens 3 is rotated in theattaching direction 44 further from the attachment position with respectto the camera body 2, the restriction pin 315 abuts on the rear end ortrailing end of the fourth body-side claw portion 290 d in the attachingdirection 44, and further rotation of the interchangeable lens 3 withrespect to the camera body 2 is prevented.

Explanation of Over-Rotated State in Removing Direction

An over-rotated state where the interchangeable lens 3 is rotated fromthe insertion position in a direction opposite to the attachingdirection 44 (removing direction) with respect to the camera body 2 willbe described next with reference to FIG. 11. FIG. 11 is a diagram ofpart of the lens mount mechanism in the over-rotated state in theremoving direction, as seen from a side. Because as shown in FIG. 7, therestriction pin 315 is disposed at a trailing end portion of the fourthlens-side claw portion 390 d in the attaching direction 44, if the usertries to inversely rotate the interchangeable lens 3 after theinterchangeable lens 3 is inserted into the camera body 2, therestriction pin 315 abuts on a tip of the third body-side claw portion290 c in the attaching direction 44, so that further rotation of theinterchangeable lens 3 in the removing direction with respect to thecamera body 2 is prevented.

In this manner, by the restriction pin 315 abutting on the end portionof the body-side claw portion 290 in the circumferential direction, bothover rotation in the attaching direction 44 and over rotation in theremoving direction are prevented. Because the restriction pin 315prevents both the over rotation in the attaching direction 44 and theover rotation in the removing direction, it is not necessary to preparetwo members for preventing over rotation in the attaching direction 44and for preventing over rotation in the removing direction.

Further, because the restriction pin 315 prevents over rotation byutilizing the end portion of the body-side claw portion 290 in thecircumferential direction, it is not necessary to separately provide amember which abuts on the restriction pin 315 upon over rotation.

Explanation of Erroneous Insertion State

An erroneous insertion state where the user tries to insert theinterchangeable lens 3 into the camera body 2 at a wrong positionwithout aligning the index of the interchangeable lens 3 and the indexof the camera body 2 will be described next. Because the lens-side clawportion 390 does not pass through the body-side through portion 280 inan erroneous insertion state, positional relationship between thelens-side claw portion 390 and the body-side claw portion 290 on theoptical axis O is different from positional relationship at theinsertion position. FIG. 12 and FIGS. 13A,13B and 13C are schematicdiagrams illustrating positional relationship between the body-side clawportion 290 of the camera body 2 and the lens-side claw portion 390 ofthe interchangeable lens 3, and are diagrams for making a state wherethe claw portions abut on each other understandable. Further, FIG. 12and FIGS. 13A,13B and 13C are diagrams of the body-side mount 210 andthe lens-side mount 310, as seen from the subject side to the imagesensor 270 side (seen in the +Z direction), and the lens-side mount 310is horizontally inverted between FIG. 5 and FIG. 6. As an example of theerroneous insertion state, a state where the index of theinterchangeable lens 3 and the index of the camera body 2 are displacedfrom the insertion position in the removing direction by 15 degrees isillustrated in FIG. 12. Further, states where the index of theinterchangeable lens 3 and the index of the camera body 2 are displacedfrom the insertion position at intervals of 90 are illustrated in FIG.13A to FIG. 13C.

FIG. 12 illustrates a state where the indexes are displaced from theinsertion position in the removing direction by 15 degrees (firsterroneous insertion state). As indicated with hatching in FIG. 12,because the lens-side claw portion 390 abuts on the body-side clawportion 290 at portions indicated with four reference signs γ1 to γ4,the lens-side claw portion 390 is not inserted into the body-sidethrough portion 280. That is, in the first erroneous insertion state, bythe lens-side claw portion 390 abutting on the body-side claw portion290 at four portions, erroneous insertion is reliably prevented.

FIG. 13A is a diagram illustrating a state where the index of theinterchangeable lens 3 and the index of the camera body 2 are displacedfrom the insertion position in the removing direction by approximately90 degrees (second erroneous insertion state). FIG. 13B is a diagramillustrating a third erroneous insertion state where the index of theinterchangeable lens 3 and the index of the camera body 2 are displacedfrom the insertion position in the removing direction by approximately180 degrees. FIG. 13C is a diagram illustrating a fourth erroneousinsertion state where the index of the interchangeable lens 3 and theindex of the camera body 2 are displaced from the insertion position inthe removing direction by approximately 270 degrees.

As illustrated in FIG. 13A, in a case of the second erroneous insertionstate, because the third lens-side claw portion 390 c abuts on the firstbody-side claw portion 290 a at a portion indicated with a referencesign γ5, and abuts on the second body-side claw portion 290 b at aportion indicated with γ7, the third lens-side claw portion 390 c cannotbe inserted into the second body-side through portion 280 b. Further,because the first lens-side claw portion 390 a abuts on the fourthbody-side claw portion 290 d at a portion indicated with a referencesign γ6, the first lens-side claw portion 390 a cannot be inserted intothe fourth body-side through portion 280 d. In this manner, in thesecond erroneous insertion state, by the lens-side claw portion 390abutting on the body-side claw portion 290 at three portions, erroneousinsertion is prevented.

As illustrated in FIG. 13B, in a case of the third erroneous insertionstate, because the fourth lens-side claw portion 390 d abuts on thefirst body-side claw portion 290 a at a portion indicated with areference sign γ8, the fourth lens-side claw portion 390 d cannot beinserted into the second body-side through portion 280 b. Further,because the first lens-side claw portion 390 a abuts on the thirdbody-side claw portion 290 c at a portion indicated with a referencesign γ9, the first lens-side claw portion 390 a cannot be inserted intothe first body-side through portion 280 a. In this manner, in the thirderroneous insertion state, by the lens-side claw portion 390 abutting onthe body-side claw portion 290 at two portions, erroneous insertion isprevented.

As illustrated in FIG. 13C, in a case of the fourth erroneous insertionstate, because the first lens-side claw portion 390 a abuts on the firstbody-side claw portion 290 a at a portion indicated with a referencesign γ10 and abuts on the second body-side claw portion 290 b at aportion indicated with γ11, the first lens-side claw portion 390 acannot be inserted into the second body-side through portion 280 b.Further, because the third lens-side claw portion 390 c abuts on thethird body-side claw portion 290 c at a portion indicated with areference sign γ12, the third lens-side claw portion 390 c cannot beinserted into the fourth body-side through portion 280 d. In thismanner, in the fourth erroneous insertion state, by the lens-side clawportion 390 abutting on the body-side claw portion 290 at threeportions, erroneous insertion is prevented.

(1) As described above, in the erroneous insertion states other than theinsertion state where the interchangeable lens 3 is in a insertionposition, by the lens-side claw portion 390 abutting on the body-sideclaw portion 290 at at least two portions, the lens-side claw portion390 is prohibited from being inserted into the body-side through portion280 at positions other than the insertion position. Therefore, even ifit is tried to attach the interchangeable lens 3 to the camera body 2 atthe erroneous insertion positions, by the claw portions abutting on eachother at at least two portions, erroneous insertion is reliablyprevented.

(2) Further, in the first erroneous insertion state to the fourtherroneous insertion state, one of two or more abutment positions islocated above the upper side of the image sensor 270. That is, at theerroneous insertion positions, by one of the first lens-side clawportion 390 a to the third lens-side claw portion 390 c abutting on anend portion of a leading side of the first body-side claw portion 290 ain the attaching direction 44, insertion of the first lens-side clawportion 390 a, the third lens-side claw portion 390 c and the forthlens-side claw portion 390 d other than the second lens-side clawportion 390 b into the second body-side through portion 280 b isprevented.

(3) As mentioned above, the body-side terminal holding unit 220 isdisposed within the opening 212 of the body-side mount 210 and above theupper side of the image sensor 270. The first body-side claw portion 290a is located above the body-side terminal holding unit 220, and a lengthof the first body-side claw portion 290 a in the circumferentialdirection is the longest among the four body-side claw portions 290.Further, the second body-side through portion 280 b is located above thebody-side terminal holding unit 220, and the second body-side throughportion 280 b is the shortest among the four body-side through portions280. Therefore, only the second lens-side claw portion 390 b is capableof being inserted into the second body-side through portion 280 b at aproper insertion position, and other first lens-side claw portion 390 ato the third lens-side claw portion 390 c are not erroneously insertedinto the second body-side through portion 280 b.

Further, even if the first lens-side claw portion 390 a to the thirdlens-side claw portion 390 c tilt (tilt in a direction intersecting withthe optical axis O direction), the first lens-side claw portion 390 a tothe third lens-side claw portion 390 c do not go into the secondbody-side through portion 280 b.

By this means, the lens-side claw portions 390 a to 390 c are preventedfrom colliding with the body-side terminal holding unit 220 and damagingthe body-side terminals in the erroneous insertion states.

(4) Further, while erroneous insertion of the lens-side claw portions390 is prevented by the first body-side claw portion 290 a abutting onone of the lens-side claw portions 390 in the erroneous insertionstates, because the length of the first body-side claw portion 290 a inthe circumferential direction is the longest among the four body-sideclaw portions 290 and the first body-side claw portion 290 a has highrigidity, it is possible to lower a possibility that the first body-sideclaw portion 290 a is broken upon erroneous insertion.

(5) Further, in the second to the fourth erroneous insertion states, atleast one of the abutment positions is located at a position oppositethe body-side terminal holding unit 220 in relation to the optical axisO. That is, one of the abutment positions is located near the body-sideterminal holding unit 220 and above the second body-side line B2 (seeFIG. 2) which passes through the optical axis O, and another one of theabutment positions is located below the second body-side line B2 whichpasses through the optical axis O. Therefore, while only there are twoor three abutment positions in the second to the fourth erroneousinsertion states, because the claw portions respectively abut above andbelow the second body-side line B2 which passes through the optical axisO, it is possible to lower a possibility of erroneous insertion.

(6) Further, in the first to fourth erroneous insertion states, one ofthe two or more abutment positions is located on an outer periphery sideof the lens-side terminal holding unit 320. That is, in the erroneousinsertion positions, one of the first to fourth body-side claw portions290 a to 290 d abuts on an end portion of a tip side of the firstlens-side claw portion 390 a in the attaching direction 44. Therefore,erroneous insertion of other second to fourth body-side claw portions290 b to 290 d into the second lens-side through portion 380 b isprevented. In short, the lens-side terminals are protected.

(7) As mentioned above, there is an end portion of a tip side of thefirst body-side claw portion 290 a in the attaching direction 44, abovethe lens-side terminal holding unit 320. By this means, the firstlens-side claw portion 390 a is prevented from passing through thebody-side through portions 280 b to 280 d other than the first body-sidethrough portion 280 a, colliding with the lens-side terminal holdingunit 320 and damaging the lens-side terminals.

(8) Further, while erroneous insertion of the first lens-side clawportion 390 a is prevented by the first lens-side claw portion 390 aabutting on one of the body-side claw portions 290 in the erroneousinsertion states, because a length of the first lens-side claw portion390 a in the circumferential direction is the second longest among thefour lens-side claw portions 390 and the first lens-side claw portion390 a has relatively high rigidity, it is possible to lower apossibility that the first lens-side claw portion 390 a is broken uponerroneous insertion.

(9) Here, as illustrated in FIG. 8, the second lens-side claw portion390 b passes through the second body-side through portion 280 b to bedisposed at the insertion position, and then faces the second body-sideclaw portion 290 b at the attachment position. The angle α6 (FIG. 6) ofthe second lens-side claw portion 390 b is smaller than the angle β2(FIG. 3) of the second body-side through portion 280 b. The angle β2 ofthe second body-side through portion 280 b is smaller than the firstrotating angle from the insertion position to the attachment position.

Therefore, by making the second lens-side claw portion 390 b smallerthan the first rotating angle, it is possible to make the secondbody-side through portion 280 b smaller and prevent other lens-side clawportions 390 other than the second lens-side claw portion 390 b frompassing through the second body-side through portion 280 b in theerroneous insertion state.

Particularly, in the second erroneous insertion state to the fourtherroneous insertion state where there are two or three portions at whichthe lens-side claw portion 390 abuts on the body-side claw portion 290,it is possible to prevent other lens-side claw portions 390 a, 390 c and390 d other than the second lens-side claw portion 390 b from passingthrough the second body-side through portion 280 b.

(10) Because the body-side terminal holding unit 220 is disposed on aninner diameter side of the second body-side through portion 280 b, bythe above-described other lens-side claw portions 390 a, 390 c and 390 dbeing prevented from passing through, it is also possible to prevent theother lens-side claw portions 390 and the cylindrical portion 312 fromcolliding with the body-side terminal holding unit 220 and breaking thebody-side terminals.

(11) Note that the angle α6 of the second lens-side claw portion 390 bmay be smaller than the angles α5, α7 and α8 of the first lens-side clawportion 390 a, the third lens-side claw portion 390 c and the fourthlens-side claw portion 390 d. The angle β2 of the second body-sidethrough portion 280 b may be smaller than the angles α5, α7 and α8 ofthe above-described first lens-side claw portion 390 a, the thirdlens-side claw portion 390 c and the fourth lens-side claw portion 390d.

According to the above-described embodiment, it is possible to properlyattach the interchangeable lens 3 to the camera body 2 in a usablemanner. Particularly, because the four lens-side claw portions 390 arerespectively pressed in the +Z direction from the flat springs 213 ofthe four body-side claw portions 290 once the interchangeable lens 3 isattached to the camera body 2, even in the case where one of theinterchangeable lens 3 and the camera body 2 is subjected to impact,because there are respectively four projecting portions (the lens-sideclaw portion 390, the body-side claw portion 290), high impactresistance is provided.

Further, once the interchangeable lens 3 is attached to the camera body2, it is possible to perform communication, power supply and controlbetween the camera body 2 and the interchangeable lens 3 throughrespective terminals of the camera body 2 and the interchangeable lens3, so that it is possible to properly use the camera system 1.

The four projecting portions of the interchangeable lens 3 are disposedon two lines intersecting with a line connecting the center of a contactpoint holding unit and the optical axis O at approximately 45 degrees onthe optical axis O, come into contact with the four flat springs 213disposed around the optical axis O at intervals of approximately 90degrees and face the four projecting portions of the camera body 2. Bythis means, high impact resistance is provided both in the case wherethe camera system 1 is laterally or horizontally held and longitudinallyheld. Particularly, even if one of the interchangeable lens 3 and thecamera body 2 is subjected to impact in a vertical direction, becausetwo projecting portions are disposed each on the right side and on theleft side of the lines (B1, L1 shown in FIGS. 5 and 7) connecting thecenter of the contact point holding unit and the optical axis O, it ispossible to receive impact in the vertical direction at two or moreprojecting portions.

Referring to FIG. 2, the second body-side claw portion 290 b and thefourth body-side claw portion 290 d are disposed on the third body-sideline B3, and the first body-side claw portion 290 a and the thirdbody-side claw portion 290 c are disposed on the fourth body-side lineB4. Here, the angle α4 of the fourth body-side claw portion 290 d is thethird largest among the four body-side claw portions 290, and the angleα2 of the second body-side claw portion 290 b is the smallest (fourthlargest) among the four body-side claw portions 290. Further, the angleα1 of the first body-side claw portion 290 a is the largest among thefour body-side claw portions 290, and the angle α3 of the thirdbody-side claw portion 290 c is the second largest among the fourbody-side claw portions.

Therefore, in the case where one of the interchangeable lens 3 and thecamera body 2 is subjected to impact in a vertical direction, forceapplied to combination of the two projecting portions on the upper side(the first body-side claw portion 290 a and the second body-side clawportion 290 b) becomes substantially equal to force applied tocombination of the two projecting portions on the lower side (the fourthbody-side claw portion 290 d and the third body-side claw portion 290c). Also in the case where one of the interchangeable lens 3 and thecamera body 2 is subjected to impact in a horizontal direction, forceapplied to combination of the two projecting portions on the left side(the third body-side claw portion 290 c and the second body-side clawportion 290 b) becomes substantially equal to force applied tocombination of the two projecting portions on the right side (the firstbody-side claw portion 290 a and the fourth body-side claw portion 290d).

Referring to FIG. 5, the first lens-side claw portion 390 a and thethird lens-side claw portion 390 c are disposed on the third lens-sideline L3, and the second lens-side claw portion 390 b and the fourthlens-side claw portion 390 d are disposed on the fourth lens-side lineL4. Here, the angle α8 of the fourth lens-side claw portion 390 d is thethird largest among the four lens-side claw portion 390, and the angleα6 of the second lens-side claw portion 390 b is the smallest (thefourth largest) among the four lens-side claw portions 390. Further, theangle α5 of the first lens-side claw portion 390 a is the second largestamong the four lens-side claw portions, and the angle α7 of the thirdlens-side claw portion 390 c is the largest among the four lens-sideclaw portions.

Therefore, in the case where one of the interchangeable lens 3 and thecamera body 2 is subjected to impact in a vertical direction, forceapplied to combination of the two projecting portions on the upper side(the first lens-side claw portion 390 a and the second lens-side clawportion 390 b) becomes substantially equal to force applied tocombination of the two projecting portions on the lower side (the fourthlens-side claw portion 390 d and the third lens-side claw portion 390c). Also in the case where one of the interchangeable lens 3 and thecamera body 2 is subjected to impact in a horizontal direction, forceapplied to combination of the two projecting portions on the left side(the first lens-side claw portion 390 a and the fourth lens-side clawportion 390 d) becomes substantially equal to force applied tocombination of the two projecting portions on the right side (the thirdlens-side claw portion 390 c and the second lens-side claw portion 390b).

Further, in the present embodiment, the angle of the third lens-sideclaw portion 390 c is larger among the first lens-side claw portion 390a and the third lens-side claw portion 390 c disposed on the thirdlens-side line L3, and the angle of the fourth lens-side claw portion390 d is larger among the second lens-side claw portion 390 b and thefourth lens-side claw portion 390 d disposed on the fourth lens-sideline L4. That is, the two lens-side claw portions 390 on the lower sideof the second lens-side line L2 (extending in a horizontal direction)are larger among the two lens-side claw portions 390 facing across theoptical axis O. Therefore, it is possible to receive impact received onthe interchangeable lens 3 from a lower direction with a large area ofthe two lens-side claw portions 390 with the large angle on the lowerside of the second lens-side line L2 in a state where the camera systemis horizontally held. Further, in the case where the interchangeablelens 3 is subjected to impact from a lower direction in a state wherethe camera system is horizontally held, the lens-side claw portions 390on the lower side of the second lens-side line L2 are subjected toimpact in a direction (−Z direction) closer to the body-side clawportion 290. Here, the flat spring 213 presses the lens-side clawportion 390 in a direction (+Z direction) away from the body-side clawportion 290. Therefore, even if the interchangeable lens 3 is subjectedto impact from a lower direction in a state where the camera system ishorizontally held, because the lens-side claw portions 390 on the lowerside of the second lens-side line L2 can absorb impact with a large areaand also with urging force of the flat springs 213 of the body-side clawportions 290 which face each other, high impact resistance is provided.

The lens-side terminal holding unit 320 is disposed above the imagesensor 270 in a state where the interchangeable lens 3 is attached tothe camera body 2. Because sunlight incident on the interchangeable lens3 is incident on a lower side on an exit side of the interchangeablelens 3 in a state where the camera system 1 is horizontally held. Inthis situation, while ghost is likely to occur on the lower side of theimage sensor 270, because, in the present embodiment, the lens-sideterminal holding unit 320 is disposed not below but above the imagesensor 270, it is possible to suppress ghost.

The four flat springs 213 are disposed around the optical axis O atintervals of approximately 90 degrees. Therefore, at least two flatsprings 213 among the four flat springs 213 come into contact with thetwo lens-side claw portions 390 across the optical axis O, and the twolens-side claw portions 390 are pressed in the +Z direction. In thepresent embodiment, the interchangeable lens 3 includes four lens-sideclaw portions 390, even in the case where one lens-side claw portion 390among the four lens-side claw portions 390 of the interchangeable lens 3is broken, because at least two lens-side claw portions 390 are disposedat positions facing each other across the optical axis O, the lens-sideclaw portion 390 is pressed with the two flat springs 213 disposed atpositions facing each other across the optical axis O. Therefore, it ispossible to provide the camera system 1 in which the interchangeablelens 3 can be attached to the camera body 2 in a usable manner even ifthe lens-side claw portions 390 of the interchangeable lens 3 are brokenand the number of lens-side claw portions 390 becomes insufficient.

Further, because the flat spring 213 is located on the line B5 (FIG. 4),it is possible to strongly press the lens-side terminals near the lineB5 to the body-side terminals.

It is also possible to make the following modifications and alsopossible to combine one or a plurality of modified examples with theabove-described embodiment.

Modified Examples

It is also possible to employ a configuration where one of the fourlens-side claw portions 390 is removed, and three lens-side clawportions are provided. Because the flat springs 213 of the camera body 2are disposed around the optical axis O at intervals of 90 degrees evenif there are three lens-side claw portions, it is possible to attach theinterchangeable lens 3 in a usable manner by the lens-side claw portionsbeing pressed from at least three flat springs 213.

It is also possible to employ a configuration where two lens-side clawportions 390 which faces each other across the optical axis O areremoved among the four lens-side claw portions 390, and two lens-sideclaw portions which face each other across the optical axis O areprovided. Even if there are two lens-side claw portions, because thelens-side claw portions are disposed to face each other across theoptical axis O and the flat springs of the camera body 2 are disposedaround the optical axis at intervals of 90 degrees, it is possible toattach the interchangeable lens 3 in a usable manner by the lens-sideclaw portions being pressed from at least the flat springs 213 facingeach other across the optical axis O.

Note that, in the case where a configuration is employed where twolens-side claw portions facing each other across the optical axis O areprovided, it is preferable that one of the two lens-side claw portionsis disposed at a position close to the center of the lens-side terminalholding unit 320. By the lens-side claw portion being disposed at aposition close to the center of the lens-side terminal holding unit 320and brought into contact with the flat spring 213, it is possible toproperly use the camera system 1 while bringing the lens-side terminalscontact with the body-side terminals.

A material of the lens-side mount 310 is not particularly limited, andmay be a metal or a resin. Further, an end portion of the lens-sidemount 310 (such as an end portion of an outer periphery side of thelens-side claw portion 390, an end portion of the lens-side claw portion390 in a circumferential direction, and an end portion of thecylindrical portion 312 in the optical axis O direction) may be formedsuch that at least part is sloped. An end portion of the lens-side mount310 does not have to be sloped and may be partially stepped.

A shape of the lens-side terminal holding unit 320 is not particularlylimited, and can be changed as appropriate. Particularly, by causing theend portion of the lens-side terminal holding unit 320 in thecircumferential direction to be sloped, it is possible to smoothly bringthe lens-side terminal holding unit 320 into contact with the body-sideterminal holding unit 220 while the interchangeable lens 3 is rotatedfrom the insertion position to the attachment position.

Further, while the lens-side terminal holding unit 320 includes aplurality of lens-side terminals disposed in an arc shape, the positionsof the lens-side terminals may be displaced as long as the lens-sideterminals come into contact with the body-side terminals once theinterchangeable lens 3 is attached to the camera body 2.

A central position and a length of the lens-side claw portion 390 in thecircumferential direction can be changed as appropriate within a rangewhere the lens-side claw portion 390 can be pressed from the flat spring213 at the attachment position. The central position of the lens-sideclaw portion 390 in the circumferential direction and the centralposition of the urged portion in the circumferential direction may belocated at different positions. That is, a position where the lens-sideclaw portion 390 is pressed from the central position of the flat spring213 in the circumferential direction may be different from the centralposition of the lens-side claw portion 390 in the circumferentialdirection. In a similar manner, the central position of the lens-sideclaw portion 390 in the circumferential direction does not have tocoincide with the central position of the body-side claw portion 290 inthe circumferential direction at the attachment position. Further, thelength of the lens-side claw portion 390 in the circumferentialdirection does not have to be the same as the length of thecorresponding body-side claw portion 290 in the circumferentialdirection.

Note that, while, in the present embodiment, the interchangeable lens 3of the camera system 1 has been described as an example of theaccessory, the accessory is not limited to the interchangeable lens 3.For example, a tele converter, a wide converter, a close-up ring, or thelike, which is attached between the camera body 2 and theinterchangeable lens 3, and which changes a focal length of theinterchangeable lens 3 may be used. Alternatively, it is also possibleto apply the present invention to a mount adapter, or the like, whichenables an accessory including the interchangeable lens 3 conforming tomount standards other than the mount standards of the camera body 2 tobe able to be attached to the above-mentioned camera body 2. That is,the present invention can be similarly applied to any accessory which isused by being attached to the mount of the camera body 2. In this case,the lens-side claw portion, the lens-side terminal, or the like,respectively correspond to an accessory side projecting portion, anaccessory side terminal, or the like, of the accessory.

While, in the above-described embodiment, the accessory which can beremovably attached to the camera body 2 is used, the above-describedcamera body 2 may be a mount adapter which enables the interchangeablelens 3 conforming to the above-mentioned mount standards to be attachedto a camera body which conforms to mount standards different from theabove-mentioned mount standards, and it is also possible to employ aconfiguration where the above-mentioned accessory can be attached to themount adapter.

While, various embodiments and modified examples have been describedabove, the present invention is not limited to these contents. Otheraspects which can be considered within a scope of the technical idea ofthe present invention are incorporated into the scope of the presentinvention.

The invention claimed is:
 1. An accessory which can be removablyattached to a camera body, including: an image sensor which has arectangular shape having an upper side, a lower side, a right side and aleft side in a case where the camera body is horizontally held, theimage sensor receiving incident subject light centering around anoptical axis; a body-side terminal group including a plurality ofbody-side terminals disposed above the upper side of the image sensor; aring-shaped body-side mount disposed outside the image sensor and thebody-side terminal group, and having a ring shape formed centeringaround the optical axis; a first body-side projecting portion projectingfrom the body-side mount in an inner diameter direction; a first elasticmember disposed on an image side of the first body-side projectingportion; a second body-side projecting portion projecting from thebody-side mount in the inner diameter direction; a second elastic memberdisposed on an image side of the second body-side projecting portion; athird body-side projecting portion projecting from the body-side mountin the inner diameter direction; a third elastic member disposed on animage side of the third body-side projecting portion; a fourth body-sideprojecting portion projecting from the body-side mount in the innerdiameter direction; and a fourth elastic member disposed on an imageside of the fourth body-side projecting portion; wherein the firstelastic member, the second elastic member, the third elastic member andthe fourth elastic member are respectively disposed in four regionsdivided by a first body-side line which passes through a center in acircumferential direction of the body-side terminal group and theoptical axis, and a second body-side line which is orthogonal to thefirst body-side line at the optical axis; the accessory comprising: anaccessory-side mount of a ring shape centering around the optical axis,the accessory-side mount being configured to be in contact with thebody-side mount; a cylindrical portion extending in the optical axisdirection from an inner peripheral edge portion of the accessory-sidemount; an accessory-side terminal group disposed inside the cylindricalportion, the accessory-side terminal group including a plurality ofaccessory-side terminals configured to be in contact with the body-sideterminals upon attachment to the camera body; a first accessory-sideprojecting portion projecting from the cylindrical portion in an outerperiphery direction of the accessory-side mount and extending in acircumferential direction around the optical axis; and a thirdaccessory-side projecting portion projecting from the cylindricalportion in the outer periphery direction of the accessory-side mount andextending in the circumferential direction around the optical axis;wherein: positions of the first accessory-side projecting portion andthe third accessory-side projecting portion are fixed with respect tothe accessory-side mount, the cylindrical portion and the accessory-sideterminal group; and the first accessory-side projecting portion and thethird accessory-side projecting portion are disposed opposite to eachother across the optical axis so as to contact with two elastic membersopposite to each other across the optical axis among the first elasticmember, the second elastic member, the third elastic member and thefourth elastic member upon attachment to the camera body.
 2. Theaccessory according to claim 1, wherein: a first center angle formed bya line connecting one end of the first accessory-side projecting portionin the circumferential direction and the optical axis and a lineconnecting the other end of the first accessory-side projecting portionin the circumferential direction and the optical axis is different froma third center angle formed by a line connecting one end of the thirdaccessory-side projecting portion in the circumferential direction andthe optical axis and a line connecting the other end of the thirdaccessory-side projecting portion in the circumferential direction andthe optical axis.
 3. The accessory according to claim 1, wherein: thefirst accessory-side projecting portion includes a first contact portionwhich is in contact with the first elastic member; the first contactportion extends in the circumferential direction around the opticalaxis; and a central position of the first contact portion in thecircumferential direction is located at a position different from acentral position of the first accessory-side projecting portion in thecircumferential direction.
 4. The accessory according to claim 1,wherein: the first accessory-side projecting portion includes a firstcontact portion which is in contact with the first elastic member; andat least part of the accessory-side terminal group is disposed on aninner side of the first contact portion.
 5. The accessory according toclaim 1, wherein: the first accessory-side projecting portion includes afirst contact portion which is in contact with the first elastic member;the third accessory-side projecting portion includes a third contactportion which is in contact with the third elastic member; one end ofthe accessory-side terminal group is disposed on an inner side of thefirst contact portion; and the first contact is disposed opposite to thethird contact portion across the optical axis.
 6. The accessoryaccording to claim 1, further comprising: a second accessory-sideprojecting portion projecting from the cylindrical portion in the outerperiphery direction of the accessory-side mount and extending in thecircumferential direction around the optical axis; and a fourthaccessory-side projecting portion projecting from the cylindricalportion in the outer periphery direction of the accessory-side mount andextending in the circumferential direction around the optical axis,wherein: the first accessory-side projecting portion is in contact withthe first elastic member; the second accessory-side projecting portionis in contact with the second elastic member; the third accessory-sideprojecting portion is in contact with the third elastic member, and thefourth accessory-side projecting portion is in contact with the fourthelastic member.
 7. The accessory according to claim 6, wherein: thefirst accessory-side projecting portion and the third accessory-sideprojecting portion are disposed on an third accessory-side lineintersecting with an accessory-side first line which passes through acenter of the accessory-side terminal group and the optical axis, at theoptical axis at approximately 45 degrees, and the second accessory-sideprojecting portion and the fourth accessory-side projecting portion aredisposed on an fourth accessory-side line which is orthogonal to thethird accessory-side line at the optical axis.
 8. The accessoryaccording to claim 6, wherein: the first accessory-side projectingportion includes a first contact portion which is in contact with thefirst elastic member; the second accessory-side projecting portionincludes a second contact portion which is in contact with the secondelastic member; the third accessory-side projecting portion includes athird contact portion which is in contact with the third elastic member;the fourth accessory-side projecting portion includes a fourth contactportion which is in contact with the fourth elastic member; and thefirst contact portion, the second contact portion, the third contactportion and the fourth contact portion are disposed around the opticalaxis at intervals of 90 degrees.
 9. The accessory according to claim 6,wherein: a third center angle formed by a line connecting one end of thethird accessory-side projecting portion in the circumferential directionand the optical axis and a line connecting the other end of the thirdaccessory-side projecting portion in the circumferential direction andthe optical axis is larger than a first center angle formed by a lineconnecting one end of the first accessory-side projecting portion in thecircumferential direction and the optical axis and a line connecting theother end of the first accessory-side projecting portion in thecircumferential direction and the optical axis; the first center angleis larger than a fourth center angle formed by a line connecting one endof the fourth accessory-side projecting portion in the circumferentialdirection and the optical axis and a line connecting the other end ofthe fourth accessory-side projecting portion in the circumferentialdirection and the optical axis; and the fourth center angle is largerthan a second center angle formed by a line connecting one end of thesecond accessory-side projecting portion in the circumferentialdirection and the optical axis and a line connecting the other end ofthe second accessory-side projecting portion in the circumferentialdirection and the optical axis; further wherein: the firstaccessory-side projecting portion and the third accessory-sideprojecting portion are disposed on a third accessory-side lineintersecting with an accessory-side first line which passes through acenter of the accessory-side terminal group and the optical axis, at theoptical axis at approximately 45 degrees; and the second accessory-sideprojecting portion and the fourth accessory-side projecting portion aredisposed on a fourth accessory-side line which is orthogonal to thethird accessory-side line at the optical axis.
 10. The accessoryaccording to claim 6, wherein: the accessory is attachable to the camerabody by being rotated by a first angle in a first direction in a planewhich is substantially orthogonal to the optical axis at a predeterminedposition on the optical axis from an insertion position where the firstaccessory-side projecting portion to the fourth accessory-sideprojecting portion are inserted between the respectively correspondingbody-side projecting portions at the predetermined position, to anattachment position where the first accessory-side projecting portion tothe fourth accessory-side projecting portion face the respectivelycorresponding body-side projecting portions.
 11. The accessory accordingto claim 10, wherein: at an erroneous insertion position which is aposition different from the insertion position on the optical axis, atleast two among the first accessory-side projecting portion, the secondaccessory-side projecting portion, the third accessory-side projectingportion and the fourth accessory-side projecting portion abut at leasttwo among the first body-side projecting portion, the second body-sideprojecting portion, the third body-side projecting portion and thefourth body-side projecting portion.
 12. The accessory according toclaim 10, wherein: at an erroneous insertion position which is aposition different from the insertion position on the optical axis, oneof the first accessory-side projecting portion, the secondaccessory-side projecting portion, the third accessory-side projectingportion and the fourth accessory-side projecting portion abuts the firstbody-side projecting portion located above the body-side terminal group.13. The accessory according to claim 10, wherein: at an erroneousinsertion position which is a position different from the insertionposition on the optical axis, the first accessory-side projectingportion which is the closest to a center of the accessory-side terminalgroup abuts at least one of the first body-side projecting portion, thesecond body-side projecting portion, the third body-side projectingportion and the fourth body-side projecting portion.
 14. The accessoryaccording to claim 10, wherein: a center angle of at least one of thefirst accessory-side projecting portion, the second accessory-sideprojecting portion, the third accessory-side projecting portion and thefourth accessory-side projecting portion, which is formed by a lineconnecting one end of a corresponding accessory-side projecting portionin the circumferential direction and the optical axis and a lineconnecting the other end of the corresponding accessory-side projectingportion in the circumferential direction and the optical axis is smallerthan the first angle.
 15. An accessory which can be removably attachedto a camera body including: an image sensor receiving incident subjectlight centering around an optical axis; a ring-shaped body-side mountdisposed outside the image sensor, the ring-shaped body-side mount beingformed centering around the optical axis; a plurality of body-sideprojecting portions projecting from the body-side mount in an innerdiameter direction; and a plurality of elastic members respectivelydisposed on image sides of the body-side projecting portions, theaccessory comprising: an accessory-side mount of a ring shape centeringaround the optical axis, the accessory-side mount being configured to bein contact with the body-side mount; a cylindrical portion extending inthe optical axis direction from an inner periphery edge portion of theaccessory-side mount; a first accessory-side projecting portionprojecting from the cylindrical portion in an outer periphery directionof the accessory-side mount and extending in a circumferential directionaround the optical axis; and a third accessory-side projecting portionprojecting from the cylindrical portion in the outer periphery directionof the accessory-side mount and extending in the circumferentialdirection around the optical axis, wherein: positions of the firstaccessory-side projecting portion and the third accessory-sideprojecting portion are fixed with respect to the accessory-side mountand the cylindrical portion; and the first accessory-side projectingportion and the third accessory-side projecting portion are disposedopposite to each other across the optical axis so as to contact with twoelastic members opposite to each other across the optical axis among theplurality of elastic members upon attachment to the camera body.
 16. Theaccessory according to claim 15, wherein: the first accessory-sideprojecting portion includes a first contact portion which is in contactwith one of the plurality of elastic members; and at least part of anaccessory-side terminal group is disposed on an inner side of the firstcontact portion.
 17. The accessory according to claim 16, furthercomprising: a second accessory-side projecting portion projecting fromthe cylindrical portion in the outer periphery direction of theaccessory-side mount and extending in the circumferential directionaround the optical axis; and a fourth accessory-side projecting portionprojecting from the cylindrical portion in the outer periphery directionof the accessory-side mount and extending in the circumferentialdirection around the optical axis, wherein: the second accessory-sideprojecting portion includes a second contact portion which is in contactwith one of the plurality of elastic members; the third accessory-sideprojecting portion includes a third contact portion which is in contactwith one of the plurality of elastic members; the fourth accessory-sideprojecting portion includes a fourth contact portion which is in contactwith one of the plurality of elastic members; and the first contactportion, the second contact portion, the third contact portion and thefourth contact portion are disposed around the optical axis at intervalsof 90 degrees.
 18. An accessory which can be removably attached to acamera body including a body-side mount, a body-side terminal group, aplurality of body-side projecting portions and a plurality of elasticmembers respectively disposed on image sides of the plurality ofbody-side projecting portions, the accessory comprising: anaccessory-side mount of a ring shape centering around an optical axis,the accessory-side mount being in contact with the body-side mount; acylindrical portion extending in the optical axis direction from aninner peripheral edge portion of the accessory-side mount; anaccessory-side terminal group disposed inside the cylindrical portion,the accessory-side terminal group including a plurality ofaccessory-side terminals configured to be in contact with the body-sideterminals upon attachment to the camera body; a first accessory-sideprojecting portion projecting from the cylindrical portion in an outerperiphery direction of the accessory-side mount and extending in acircumferential direction centering around the optical axis; and a thirdaccessory-side projecting portion projecting from the cylindricalportion in the outer periphery direction of the accessory-side mount andextending in the circumferential direction centering around the opticalaxis, wherein: positions of the first accessory-side projecting portionand the third accessory-side projecting portion are fixed with respectto the accessory-side mount, the cylindrical portion and theaccessory-side terminal group; and the first accessory-side projectingportion and the third accessory-side projecting portion are disposedopposite to each other across the optical axis so as to contact with twoelastic members opposite to each other across the optical axis among theplurality of elastic members upon attachment to the camera body.
 19. Theaccessory according to claim 18, wherein: the accessory-side terminalsare to be in contact with a plurality of the body-side terminalsdisposed in an arc shape above an upper side of an image sensor with arectangular shape having the upper side, a lower side, a right side anda left side in a case where the camera body is horizontally held, andreceives incident subject light centering around the optical axis. 20.The accessory according to claim 1, wherein: the accessory is aninterchangeable lens.
 21. The accessory according to claim 15, wherein:the accessory is an interchangeable lens.
 22. The accessory according toclaim 18, wherein: the accessory is an interchangeable lens.